Bactericidal effects of CaO (scallop-shell powder) on foodborne pathogenic bacteria

This study was investigated the bactericidal effects of calcium oxide (CaO) on three common foodborne pathogenic bacteria: Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium. Each bacteria level was determined in a CaO solution (0.01, 0.03, 0.05, 0.10, 0.15, and 0.20% [w/v]) exposed for either 15 sec, 30 sec, 1 min, 2 min, 3 min, 5 min, 10 min, or 30 min. All three bacteria were not greatly affected by CaO solutions at concentrations of 0.01 and 0.03%, however, the decline of E. coli (99%; 2.78 log10 CFU/mL), L. monocytogens (45%; 1.44 log10 CFU/mL), and S. typhimurium (70%; 2.08 log10 CFU/mL) was greatest when they were exposed to 0.05% CaO solution for 10 min. Moreover, the bactericidal action of CaO was maintained for at least 24 h of storage. The results of this study provide evidence that CaO, as a substitute for synthetic chemical substances has potential for use in the disinfection and sanitization of foods and food processing equipment.